Prepitch: Character integer literals

Evolution Pitches
243

LOL. You’re right. And this would no longer even compile with NFx:

let scalar: Unicode.Scalar = "שּׂ"

There is a reason Swift steers people toward String and Character, and leaves Unicode.Scalar hidden away for those who know what they’re doing.

These are safe:

let string: String = "שּׂ"
let character: Character = "שּׂ"

These are dangerous and not Unicode‐compliant at the source level:

let scalar: Unicode.Scalar = "שּׂ"
let number: UInt32 = 'שּׂ'

They are only safely expressed like this:

let scalar: Unicode.Scalar = "\u{FB2D}"
let number: UInt32 = 0xFB2D
let scalar2: Unicode.Scalar(value: 0xFB2D)
let number2: UInt32 = '\u{FB2D}'

I don’t see how the last line is an improvement.

Interestingly—and very relevent—I had trouble posting this properly, because at first I was copying and pasting the character to reuse it, and Safari (or else the forum interface) was performing NFC on either the copy or the paste. In the end I had to stop copying and keep going back to the character palette to make it work properly.

Try it yourself. Copy and paste it to the text field of your own post (but don’t actually post it, or you’ll annoy us all). Then compare the bytes in the text field and the preview to the bytes where you copied it from. Not the same.

If you copy from my post to a playground, it will compile and run, but if you copy from my post to your own and then copy that to the playground, it will not compile.

(Edit: * This assumes you are using Safari and Xcode.)

I think that demonstrates fairly soundly that tools are not prepared for this sort of thing. (Even though they are Unicode‐compliant.)

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